Integer lists in Rust.

intlist.rs

// Functional-style integer lists
// Compile with "rustc -o intlist intlist.rs"

// more recent versions of the compiler need this for @ pointers
#[feature(managed_boxes)];

enum IntList {
    Empty,
    Cons(int, @IntList)
}

fn length(l: @IntList) -> uint {
    match *l {
        Empty => 0,
        Cons(_, rest) => 1 + length(rest)
    }
}

fn sum_list(l: @IntList) -> int {
    match *l {
        Empty => 0,
        Cons(i, rest) => i + sum_list(rest)
    }
}

fn main()
{
    let l1 = @Cons(5, @Cons(3, @Cons(7, @Empty)));
    println!("length of l1 is {}", length(l1));
    println!("sum of l1 is {}", sum_list(l1));
}